Aerosol generating device having an internal heater

ABSTRACT

An aerosol generating device is provided, including a storage portion to store an aerosol-forming substrate and having an outer housing and an internal passageway, the portion forming a reservoir for the substrate between the housing and the passageway; a vaporizer including an electric heater to heat the substrate to form an aerosol, the vaporizer at least partially inside the passageway; and a porous interface at least partially lining the passageway to convey the substrate towards the vaporizer, the device being electrically operated, the heater including first and second electrical connection portions, and a heating filament therebetween, a cylindrical shape of the connection portions and the filament define a cylindrical bore, an air flow route is defined through the bore, and the first connection portion being a first cylindrical electrical connection portion, the second connection portion being a second cylindrical electrical connection portion, and the filament being a cylindrical heating element.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of and claims the benefitof priority under 35 U.S.C. §120 to U.S. application Ser. No.16/171,014, filed Oct. 25, 2018, which is a continuation of U.S.application Ser. No. 14/363,531, filed on Jun. 6, 2014 (now U.S. Pat.No. 10,143,233), which is a U.S. National Stage application ofPCT/EP12/74510, filed on Dec. 5, 2012, and claims benefit of priorityunder 35 U.S.C. §119 to EP 11192696.0, filed on Dec. 8, 2011, the entirecontents of each of which are incorporated herein by reference.

The present invention relates to an aerosol generating device forheating an aerosol-forming substrate. Particularly, but not exclusively,the present invention relates to an electrically operated aerosolgenerating device for heating a liquid aerosol-forming substrate.

WO-A-2009/132793 discloses an electrically heated smoking device. Aliquid is stored in a liquid storage portion, and a capillary wick has afirst end which extends into the liquid storage portion for contact withthe liquid therein, and a second end which extends out of the liquidstorage portion. A heating element heats the second end of the capillarywick. The heating element is in the form of a spirally wound electricheating element in electrical connection with a power supply, andsurrounding the second end of the capillary wick. In use, the heatingelement may be activated by the user to switch on the power supply.Suction on a mouthpiece by the user causes air to be drawn into theelectrically heated smoking device over the capillary wick and heatingelement and subsequently into the mouth of the user.

It is an objective of the present invention to improve the generation ofaerosol in an aerosol generating device or system.

According to one aspect of the invention, there is provided an aerosolgenerating device comprising: a storage portion for storing anaerosol-forming substrate, the storage portion having an outer housingand an internal passageway, the storage portion forming a reservoir forthe aerosol-forming substrate between the outer housing and the internalpassageway; a vaporizer for heating the aerosol-forming substrate toform an aerosol, the vaporizer at least partially inside the internalpassageway in the storage portion; and a porous interface at leastpartially lining the internal passageway for conveying theaerosol-forming substrate from the storage portion towards thevaporizer.

The aerosol generating device is arranged to vaporize an aerosol-formingsubstrate to form the aerosol. The aerosol generating device may includethe aerosol-forming substrate or may be adapted to receive theaerosol-forming substrate. As known to those skilled in the art, anaerosol is a suspension of solid particles or liquid droplets in a gas,such as air.

According to another aspect of the invention, there is provided acartridge comprising: a storage portion for storing an aerosol-formingsubstrate, the storage portion having an outer housing and an internalpassageway, the storage portion forming a reservoir for theaerosol-forming substrate between the outer housing and the internalpassageway; a vaporizer for heating the aerosol-forming substrate toform an aerosol, the vaporizer at least partially inside the internalpassageway in the storage portion; and a porous interface at leastpartially lining the internal passageway for conveying theaerosol-forming substrate from the storage portion towards thevaporizer.

The aerosol generating device and cartridge may cooperate to provide anaerosol generating system for heating the aerosol-forming substrate. Thecartridge or aerosol generating device may comprise the storage portionhaving the internal passageway. The vaporizer and the porous interfacemay be contained in the aerosol generating device. The vaporizer and theporous interface may also be contained in the cartridge.

The aerosol generating device may comprise the vaporizer for heating theaerosol-forming substrate. Alternatively or additionally, the aerosolgenerating device may comprise the porous interface. The aerosolgenerating device may comprise the storage portion for storing theaerosol forming substrate.

The cartridge may comprise the vaporizer for heating the aerosol-formingsubstrate. Alternatively or additionally, the cartridge may comprise theporous interface. The cartridge may comprise the storage portion forstoring the aerosol forming substrate.

According to another aspect of the invention, there is provided anaerosol generating system comprising: a cartridge and an aerosolgenerating device, the cartridge or the aerosol generating devicecomprising: a storage portion for storing an aerosol-forming substrate,the storage portion having an internal passageway; a vaporizer forheating the aerosol-forming substrate to form an aerosol, the vaporizerat least partially inside the internal passageway in the storageportion; and a porous interface at least partially lining the internalpassageway for conveying the aerosol-forming substrate from the storageportion towards the vaporizer.

For all aspects of the invention, the storage portion may be a liquidstorage portion. For all aspects of the invention, the aerosol formingsubstrate may be a liquid aerosol forming substrate. The aerosol-formingsubstrate may contain nicotine. The aerosol-forming substrate may beadsorbed, coated, impregnated or otherwise loaded onto a carrier orsupport.

The aerosol-forming substrate may alternatively be any other sort ofsubstrate, for example, a gas substrate or a gel substrate, or anycombination of the various types of substrate. The aerosol-formingsubstrate may be a solid substrate.

The porous interface may be arranged to be in contact with liquidaerosol-forming substrate in the liquid storage portion. In oneembodiment, liquid aerosol-forming substrate in the porous interface isvaporized by the heater to form a supersaturated vapour. Thesupersaturated vapour is mixed with air. The supersaturated vapourcondenses to form the aerosol and the aerosol is carried towards themouth of a user. The liquid aerosol-forming substrate has suitablephysical properties, including surface tension and viscosity, whichallow the liquid to be transported through the porous interface.

In this invention, the vaporizer at least partially extends inside theinternal passageway of the storage portion. By having the vaporizer atleast partially inside the internal passageway, a number of advantagescan be found. First, manufacture and assembly of the aerosol generatingdevice and cartridge is easier and faster because of the simplifieddesign of the parts. Second, because the vaporizer extends at leastpartially inside the internal passageway of the storage portion ratherthan downstream of the storage portion, the length of the aerosolgenerating device and the cartridge can be optionally reduced. Third,because the vaporizer extends at least partially inside the internalpassageway of the storage portion, the vaporizer may be protected fromdamage, bending, or distortion. Fourth, the storage portion may act asan insulator which, if the vaporizer comprises a heater, may prevent thehousing of the aerosol generating device from overheating. Fifth,because the porous interface at least partially lines the internalpassageway, gravity may assist in conveying liquid from the storageportion and this reduces the chance of the porous interface drying out.Finally, any aerosol which condenses after formation may be used againby the porous interface, thereby reducing wastage and leakage.

The storage portion may protect the aerosol-forming substrate fromambient air (because air cannot generally enter the storage portion).The storage portion may protect the aerosol-forming substrate fromlight, so that the risk of degradation of the aerosol-forming substrateis significantly reduced. Moreover, a high level of hygiene can bemaintained. The storage portion may not be refillable. Thus, when theaerosol-forming substrate in the storage portion has been used up, theaerosol generating device or cartridge is replaced. Alternatively, thestorage portion may be refillable. In that case, the aerosol generatingdevice or cartridge may be replaced after a certain number of refills ofthe storage portion. The storage portion may be arranged to holdaerosol-forming substrate for a pre-determined number of puffs.Therefore, the volume of the storage portion may be expanded orcontracted based on the number of desirable puffs.

In one embodiment, the storage portion comprises a container.Preferably, the container has a constant cross sectional shape and sizealong its length. The storage portion preferably has an outer dimensiondefining the exterior of the storage portion. The outer dimension may besubstantially equal to the dimension of the aerosol generating device,thereby allowing the storage portion to cooperate effectively with theaerosol generating device. Preferably, the internal passageway has aconstant cross sectional shape and size along its length. Preferably,the internal passageway is aligned with the longitudinal axis of thestorage portion. That is to say, preferably the internal passageway is acentral passageway. Alternatively, the internal passageway may not bealigned with the longitudinal axis of the storage portion. That is tosay, the internal passageway may be off-centre. The storage portionpreferably has an inner dimension defining the dimension of the internalpassageway.

In a preferred embodiment, the storage portion comprises a prism-shapedcontainer having an annular cross section, wherein the inner radius ofthe annulus is the radius of the internal passageway of the container,and the outer radius of the annulus defines the exterior of thecontainer.

Preferably, in use, liquid is transferred from the storage portion tothe vaporizer through the porous interface. The construction of thevaporizer may enable it to be usable with a variety of different shapesand sizes of storage portion. The inner side of the porous interfacecould be in contact with the liquid in the storage portion. The outerside of the porous interface could be in contact with or adjacent thevaporizer. In one embodiment, liquid in the outer side of the porousinterface is vaporized to form the supersaturated vapour. The liquidaerosol-forming substrate has suitable physical properties, includingsurface tension and viscosity, which allow the liquid to be transportedthrough the porous interface.

The porous interface may comprise any suitable material or combinationof materials which is able to convey the aerosol-forming substratetowards the vaporizer. The porous interface may comprise a capillarymaterial, but this need not be the case. The porous interface may have afibrous or spongy structure. The porous interface may comprise a bundleof capillaries. For example, the porous interface may comprise aplurality of fibres or threads or other fine bore tubes. Alternatively,the porous interface may comprise sponge-like or foam-like material. Thestructure of the porous interface may form a plurality of small bores ortubes, through which the aerosol-forming substrate can be transported bycapillary action from the storage portion towards the vaporizer. Theparticular preferred porous material or materials will depend on thesuitable physical properties of the aerosol-forming substrate. Examplesof suitable porous materials include a sponge or foam material, ceramic-or graphite-based materials in the form of fibres or sintered powders,foamed metal or plastics material, a fibrous material, for example madeof spun or extruded fibres, such as cellulose acetate, polyester, orbonded polyolefin, polyethylene, terylene or polypropylene fibres, nylonfibres or ceramic. The porous interface may have any suitable porosityso as to be used with different liquids. The liquid has suitablephysical properties and certain parameters need to be taken intoaccount, including, but not limited to, viscosity, surface tension,density, thermal conductivity, boiling point and vapour pressure, whichallow the liquid to be transported through the porous interface.

The porous interface may have any suitable shape for cooperation withthe storage portion. Preferably, the porous interface has the same shapeand dimension as the internal passageway, thereby allowing the porousinterface to fit snugly in the internal passageway. Preferably, theporous interface fully lines the internal passageway. However, theporous interface may only partially line the internal passageway.

In a preferred embodiment, in which the storage portion comprises acontainer in the shape of a prism having an annular cross section.Preferably the porous interface comprises a hollow tube of porousmaterial, the outer dimension of the hollow tube being substantiallyequal to the diameter of the internal passageway of the storage portion.The tube of porous material may extend along all of or part of thelength of the internal passageway in the storage portion.

The vaporiser may be a heater. The heater may heat the aerosol-formingsubstrate means by one or more of conduction, convection and radiation.The heater may be an electric heater powered by an electric powersupply. The heater may alternatively be powered by a non-electric powersupply, such as a combustible fuel: for example, the heater may comprisea thermally conductive element that is heated by combustion of a gasfuel. The heater may heat the aerosol-forming substrate by means ofconduction and may be at least partially in contact with the substrate,or a carrier on which the substrate is deposited. Alternatively, theheat from the heater may be conducted to the substrate by means of anintermediate heat conductive element. Alternatively, the heater maytransfer heat to the incoming ambient air that is drawn through theaerosol-generating system during use, which in turn heats theaerosol-forming substrate by convection.

In a preferred embodiment, the aerosol generating device is electricallyoperated and the vaporizer of the aerosol generating device comprises anelectric heater for heating the aerosol-forming substrate.

The electric heater may comprise a single heating element.Alternatively, the electric heater may comprise more than one heatingelement for example two, or three, or four, or five, or six or moreheating elements. The heating element or heating elements may bearranged appropriately so as to most effectively heat theaerosol-forming substrate.

The at least one electric heating element preferably comprises anelectrically resistive material. Suitable electrically resistivematerials include but are not limited to: semiconductors such as dopedceramics, electrically “conductive” ceramics (such as, for example,molybdenum disilicide), carbon, graphite, metals, metal alloys andcomposite materials made of a ceramic material and a metallic material.Such composite materials may comprise doped or undoped ceramics.Examples of suitable doped ceramics include doped silicon carbides.Examples of suitable metals include titanium, zirconium, tantalum andmetals from the platinum group. Examples of suitable metal alloysinclude stainless steel, Constantan, nickel-, cobalt-, chromium-,aluminium- titanium- zirconium-, hafnium-, niobium-, molybdenum-,tantalum-, tungsten-, tin-, gallium-, manganese- and iron-containingalloys, and super-alloys based on nickel, iron, cobalt, stainless steel,Timetal®, iron-aluminium based alloys and iron-manganese-aluminium basedalloys. Timetal® is a registered trade mark of Titanium MetalsCorporation, 1999 Broadway Suite 4300, Denver, Colo. In compositematerials, the electrically resistive material may optionally beembedded in, encapsulated or coated with an insulating material orvice-versa, depending on the kinetics of energy transfer and theexternal physicochemical properties required. The heating element maycomprise a metallic etched foil insulated between two layers of an inertmaterial. In that case, the inert material may comprise Kapton®,all-polyimide or mica foil. Kapton® is a registered trade mark of E.I.du Pont de Nemours and Company, 1007 Market Street, Wilmington, Del.19898, United States of America.

Alternatively, the at least one electric heating element may comprise aninfra-red heating element, a photonic source or an inductive heatingelement.

The at least one electric heating element may take any suitable form.For example, the at least one electric heating element may take the formof a heating blade or heating needles or rods. Alternatively, the atleast one electric heating element may take the form of a casing orsubstrate having different electro-conductive portions, or anelectrically resistive metallic tube. The liquid storage portion mayincorporate a disposable heating element. The at least one electricheating element may comprise a flexible sheet of material. Otheralternatives include a heating wire or filament, for example a Ni—Cr(nickel-chromium), platinum, tungsten or alloy wire, or a heating plate.Optionally, the heating element may be deposited in or on a rigidcarrier material.

The at least one electric heating element may comprise a heat sink, orheat reservoir, comprising a material capable of absorbing and storingheat and subsequently releasing the heat over time to heat theaerosol-forming substrate. The heat sink may be formed of any suitablematerial, such as a suitable metal or ceramic material. Preferably, thematerial has a high heat capacity (sensible heat storage material), oris a material capable of absorbing and subsequently releasing heat via areversible process, such as a high temperature phase change. Suitablesensible heat storage materials include silica gel, alumina, carbon,glass mat, glass fibre, minerals, a metal or alloy such as aluminium,silver or lead, and a cellulose material. Other suitable materials whichrelease heat via a reversible phase change include paraffin, sodiumacetate, naphthalene, wax, polyethylene oxide, a metal, metal salt, amixture of eutectic salts or an alloy.

The heat sink may be arranged such that it is directly in contact withthe aerosol-forming substrate in the porous interface and can transferthe stored heat directly to the aerosol-forming substrate.Alternatively, the heat stored in the heat sink or heat reservoir may betransferred to the aerosol-forming substrate in the porous interface bymeans of a heat conductor, such as a metallic tube.

The at least one heating element may heat the aerosol-forming substrateby means of conduction. The heating element may be at least partially incontact with the aerosol-forming substrate. Alternatively, the heat fromthe heating element may be conducted to the aerosol-forming substrate bymeans of a heat conductor.

Alternatively or in addition, the at least one heating element maytransfer heat to the incoming ambient air that is drawn through theaerosol generating device during use, which in turn heats theaerosol-forming substrate by convection. The ambient air may be heatedbefore passing through the aerosol-forming substrate. Alternatively, theambient air may be first drawn through the aerosol-forming substrate andthen heated.

In one preferred embodiment in which the vaporizer comprises an electricheater, the electric heater comprises: a first electrical connectionportion; a second electrical connection portion; and a heating filamentbetween the first and second electrical connection portions.

In one embodiment, when the device is in use with the cartridge thefirst electrical connection portion is located at a first end of theinternal passageway, the second electrical connection portion is locatedat a second end of the internal passageway, and the heating filament hasa first end joined to the first electrical connection portion and asecond end joined to the second electrical connection portion. In thisembodiment, the first electrical connection portion, the secondconnection portion and the heating filament are manufactured separatelyand are then connected together, for example by welding. The heatingfilament may comprise a heating coil between the first and secondelectrical connection portions. Other shapes for the heating filamentare also possible.

All portions of the heating filament may have the same cross sectionalshape and area. Alternatively, some portions of the heating filament mayhave a different cross sectional shape or area from other portions ofthe heating filament.

In an alternative embodiment, the electric heater comprises a sheet ofelectrically resistive material shaped to form the first electricalconnection portion, the second electrical connection portion and theheating filament. In this embodiment, the first electrical connectionportion, the second electrical connection portion and the heatingfilament are integrally formed from the sheet of electrically resistivematerial. The term “integrally formed” refers to the first electricalconnection portion, the second electrical connection portion and theheating filament being manufactured as one single part from a singlepiece of material. Providing an integrally formed electric heatersimplifies manufacture of the heater.

The sheet of electrically resistive material may have any suitableshape. The heating filament, first electrical connection portion andsecond electrical connection portion may be formed by shaping from thesheet of electrically resistive material. For example, the heatingfilament may be cut from the sheet of electrically resistive material,for example, by a laser or by a chemical or electrical processor by highpressure water jet. Alternatively, the heating filament may bepre-formed in the desired shape.

The sheet of electrically resistive material may be a flexible sheet ofmaterial. Preferably, the flexible sheet of material is folded, rolled,curved or bent so as to form the electric heater, which is correctlyshaped to extend through the internal passageway of the liquid storageportion. The sheet of electrically resistive material may have anysuitable flexibility.

The heating filament may have the shape of a square wave extendingbetween the electrical connection portions. That is to say, the heatingfilament may comprise portions extending substantially parallel to thelongitudinal axis of the internal passageway and portions extendingsubstantially perpendicular to the longitudinal axis of the internalpassageway. The number and size of the portions extending substantiallyparallel to the longitudinal axis of the internal passageway may bevaried. The number and size of the portions extending substantiallyperpendicular to the longitudinal axis of the internal passageway may bevaried. This will affect the ultimate flexibility of the heatingelement. Alternatively, the heating filament may have any other suitableshape.

All portions of the heating filament may have the same cross sectionalshape and area. Alternatively, some portions of the heating filament mayhave a different cross sectional shape or area from other portions ofthe heating filament.

In one preferred embodiment, when the device is in use with thecartridge the electric heater at least partially inside the internalpassageway is in contact with the porous interface. This improves theheat transfer from the electric heater to the aerosol-forming substratein the porous interface.

Preferably, the electric heater is elastic. The electric heater may haveany suitable elasticity. The elasticity may provide the contact betweenthe electric heater and the porous interface. For example, if theelectric heater comprises a sheet of electrically resistive materialshaped to form the first and second electrical contact portions and theheating filament, preferably, the folding of the sheet of electricallyresistive material results in a spring effect when the electric heateris assembled. This ensures good contact with the porous interface whenthe electric heater is inside the internal passageway. This ensures aconsistent and repeatable smoking experience. In addition, this reducesthe likelihood that the electric heater will become dislodged from theinternal passageway.

Various shapes for the electric heater have been disclosed, but theskilled person will appreciate that any suitable shape may be used. Inaddition, the heating filament need not have the same shape extendingall the way between the first and second electrical connection portions.

In one preferred embodiment, the aerosol generating device iselectrically operated, the vaporizer comprises an electric heater, theliquid storage portion comprises a prism-shaped container, and theporous interface comprises a hollow tube of porous material, having aninner face in contact with liquid in the liquid storage portion and anouter face opposite the inner face, the electric heater being arrangedto heat the liquid aerosol-forming substrate near the outer face of theporous interface. Preferably, the electric heater comprises a heatingfilament in contact with the outer face of the porous interface. In thisembodiment, in use, liquid is transferred from the liquid storageportion through the porous interface lining the internal passageway.When the heater is activated, the liquid near the outer face of theporous interface is vaporized by the heater to form the supersaturatedvapour. The supersaturated vapour is mixed with and carried in the airflow through the internal passageway in the liquid storage portion.During the flow, the vapour condenses to form the aerosol and theaerosol is carried towards the mouth of a user.

However, the invention is not limited to electric heater vaporizers butmay be used in aerosol generating devices and systems in which thevapour and resulting aerosol is generated by a mechanical vaporizer, forexample but not limited to a piezo vaporizer or an atomizer usingpressurized liquid.

The storage portion and the porous interface, and optionally thevaporizer, may be removable from the aerosol generating device as asingle component.

The aerosol generating device or cartridge may comprise at least one airinlet. The aerosol generating device or cartridge may comprise at leastone air outlet. In a preferred embodiment, the aerosol generating deviceor cartridge further comprises at least one air inlet and at least oneair outlet, the air inlet and air outlet being arranged so as to definean air flow route from the air inlet to the air outlet via the internalpassageway of the storage portion.

Thus, the internal passageway may additionally act as an aerosol-formingchamber for assisting or facilitating generation of the aerosol. One ormore additional aerosol-forming chambers may be provided. The aerosol iscarried in the air flow route through the internal passageway so as toconvey the aerosol to the air outlet and into the mouth of a user. Inaddition, the size of the internal passageway may be used to assist withcontrol of the aerosol. In particular, a small internal passageway mayresult in a high air flow rate through the aerosol generating device orcartridge which may result in smaller droplets in the aerosol. A largeinternal passageway, on the other hand, may result in a low air flowrate through the aerosol generating device or cartridge which may resultin larger droplets. The droplet size in the aerosol may affect the userexperience. Preferably, the air flows through the vaporizer which hasthe same diameter as that of the internal passageway. Preferably thesize of the internal passageway, and vaporizer, is pre-set according tothe aerosol-forming substrate and the desired aerosol properties.Alternatively, however, the size of the internal passageway, andvaporizer, may be variable by a user.

In one embodiment, there is provided a nozzle arranged to extend intothe internal passageway. The nozzle allows the incoming air flow to bedirected. For example, the nozzle may allow the incoming air flow to bedirected directly onto the vaporizer, directly onto the porousinterface, across the surface of the vaporizer, across the surface ofthe porous interface, or in any other desired direction. This may affectthe aerosol formation which may, in turn affect the user experience. Inaddition, the nozzle may provide an air inlet or inlets having a smallcross section, which will increase the air flow speed. This may alsoaffect the aerosol formation by reducing the droplet size in theaerosol.

The aerosol generating device may be electrically operated and mayfurther comprise an electric power supply. The electric power supply maybe an AC power source or a DC power source. Preferably, the electricpower supply is a battery. The aerosol generating device may furthercomprise electric circuitry. In one embodiment, the electric circuitrycomprises a sensor to detect air flow indicative of a user taking apuff. In that case, preferably, the electric circuitry is arranged toprovide an electric current pulse to the vaporizer when the sensorsenses a user taking a puff. Preferably, the time-period of the electriccurrent pulse is pre-set, depending on the amount of liquid desired tobe vaporized. The electric circuitry is preferably programmable for thispurpose. Alternatively, the electric circuitry may comprise a manuallyoperable switch for a user to initiate a puff. The time-period of theelectric current pulse is preferably pre-set depending on the amount ofliquid desired to be vaporized. The electric circuitry is preferablyprogrammable for this purpose.

The liquid aerosol-forming substrate preferably has suitable physicalproperties, for example boiling point and vapour pressure, suitable foruse in the aerosol generating device or cartridge or system. If theboiling point is too high, it may not be possible to vaporize the liquidbut, if the boiling point is too low, the liquid may vaporize tooreadily. The liquid preferably comprises a tobacco-containing materialcomprising volatile tobacco flavour compounds which are released fromthe liquid upon heating. Alternatively, or in addition, the liquid maycomprise a non-tobacco material. The liquid may include aqueoussolutions, non-aqueous solvents such as ethanol, plant extracts,nicotine, natural or artificial flavours or any combination of these.Preferably, the liquid further comprises an aerosol former thatfacilitates the formation of a dense and stable aerosol. Examples ofsuitable aerosol formers are glycerine and propylene glycol.

Preferably, the aerosol generating device or cartridge comprises ahousing. Preferably, the housing is elongate. Preferably, thelongitudinal axis of the housing is substantially aligned with thelongitudinal axis of the internal passageway in the storage portion. Thehousing may comprise a shell and a mouthpiece. In that case, all thecomponents may be contained in either the shell or the mouthpiece. Inone embodiment, the housing includes a removable insert comprising thestorage portion, the vaporizer and the porous interface. In thatembodiment, those parts of the aerosol generating device may beremovable from the housing as a single component. This may be useful forrefilling or replacing the storage portion, for example.

The housing may comprise any suitable material or combination ofmaterials. Examples of suitable materials include metals, alloys,plastics or composite materials containing one or more of thosematerials, or thermoplastics that are suitable for food orpharmaceutical applications, for example polypropylene,polyetheretherketone (PEEK) and polyethylene. Preferably, the materialis light and non-brittle. The storage portion may also comprise anysuitable material or combination of materials, and may comprise the sameor different materials as the housing.

In one particularly preferred embodiment, the cartridge comprises: amouthpiece; a vaporizer comprising an electric heater for heating theaerosol-forming substrate, the heater being connectable to an electricpower supply and electric circuitry in a device; and a storage portionfor storing the aerosol forming substrate, wherein the electric heaterand a porous interface are arranged in the cartridge.

The storage portion, and optionally the porous interface and the heater,may be removable from the aerosol generating system as a singlecomponent. The storage portion, and optionally the porous interface andthe heater, may be removable from the aerosol generating system as acartridge.

Preferably, the aerosol generating device and cartridge are portable,both individually and in cooperation. Preferably, the device is reusableby a user. Preferably, the cartridge is disposable by a user, forexample when there is no more liquid contained in the liquid storageportion. The device and cartridge may cooperate to form an aerosolgenerating system which is a smoking system. The device may have a sizecomparable to a conventional cigar or cigarette. The cartridge may havea size comparable to a conventional cigar or cigarette. The smokingsystem may have a total length between approximately 30 mm andapproximately 150 mm. The smoking system may have an external diameterbetween approximately 5 mm and approximately 30 mm.

Preferably, the aerosol generating system is an electrically operatedsmoking system.

According to the invention, there is also provided an aerosol generatingsystem comprising a storage portion for storing liquid aerosol-formingsubstrate, the liquid storage portion having an internal passageway; avaporizer for heating the liquid aerosol-forming substrate to form anaerosol, the vaporizer at least partially inside the internal passagewayin the liquid storage portion; and a porous interface at least partiallylining the internal passageway for conveying the liquid aerosol-formingsubstrate from the liquid storage portion towards the vaporizer.

In one embodiment, the container is prism-shaped having an annular crosssection, the inner radius of the annulus is the radius of the internalpassageway of the container, and the outer radius of the annulus definesthe exterior of the container.

In that embodiment, the porous interface may comprise a hollow tube ofporous material, the outer dimension of the hollow tube beingsubstantially equal to the diameter of the internal passageway of thecontainer.

Preferably, the aerosol generating device is electrically operated andthe vaporizer comprises an electric heater for heating the liquidaerosol-forming substrate, the electric heater being connectable to anelectric power supply in the aerosol generating device.

In that embodiment, the electric heater is preferably in contact withthe porous interface.

In a preferred embodiment, the cartridge or the aerosol generatingdevice or both the cartridge and the aerosol generating device compriseat least one air inlet; the cartridge or the aerosol generating deviceor both the cartridge and the aerosol generating device comprise atleast one air outlet, and the air inlet and the air outlet are arranged,when the cartridge is in use with the aerosol generating device, todefine an air flow route from the air inlet to the air outlet via theinternal passageway of the container.

Features described in relation to one aspect of the invention may beapplicable to another aspect of the invention.

The invention will be further described, by way of example only, withreference to the accompanying drawings, of which:

FIG. 1 shows a perspective view of an embodiment of a cartridge for usewith an aerosol generating device according to the invention;

FIG. 2 shows a perspective exploded view of the cartridge of FIG. 1;

FIG. 3 shows a perspective view of a first embodiment of an internalheater for use with a cartridge according to the invention; and

FIG. 4 shows a perspective view of a second embodiment of an internalheater for use with a cartridge according to the invention.

FIG. 1 is a perspective view of an embodiment of a cartridge for usewith an aerosol generating device according to the invention. FIG. 2 isa perspective exploded view of the cartridge of FIG. 1. In FIGS. 1 and2, the cartridge is for use with an electrically operated aerosolgenerating device having an electric power supply and electriccircuitry.

Referring to FIGS. 1 and 2, the cartridge 100 comprises a storageportion in the form of a cylindrical container 101. Container 101 has afirst end 101 a, a second end 101 b, and an outer housing 101 c.Container 101 defines an internal passageway 103. Container 101 forms areservoir for liquid aerosol-forming substrate between the outer housing101 c of the container and the internal passageway 103. Inside theinternal passageway 103, there is provided a vaporizer (not visible inFIG. 1) in the form of internal heater 105 surrounded by a porousinterface in the form of porous tube 107. The structure of the internalheater 105 will be described further with reference to FIGS. 3 and 4. Inthis embodiment, there is further provided a separation wall 109 betweenthe porous tube 107 and container 101, closing part 111, and mouthpieceparts 113 and 115.

The cartridge 101 is arranged to be received in an aerosol generatingdevice (not shown) including an electric power supply and electriccircuitry. The aerosol generating device may further, although notnecessarily, include a puff detection device. The electric circuitry andpuff detection device may be programmable and may be used to manage theaerosol generating device operation. In this embodiment, the first end101 a of the container 101 is received closest to the electric powersupply and electric circuitry in the aerosol generating device. Theinternal heater 105 is connected to the electric power supply andelectric circuitry in the aerosol generating device. The second end 101b of the container 101 is received at the mouthpiece end of the aerosolgenerating device. The cartridge 100 or the aerosol generating device(not shown) or both the cartridge and the aerosol generating device mayinclude an air inlet, an air outlet at the mouthpiece end, and anaerosol-forming chamber.

In use, operation is as follows. Liquid aerosol-forming substrate in thereservoir formed by container 101 is conveyed through the porous tube107 towards the internal heater 105. When a user draws on the aerosolgenerating device at the mouthpiece end, ambient air is drawn through anair inlet in either the cartridge or the aerosol generating device andthrough the internal passageway 103 in the container 101. If the aerosolgenerating device includes a puff detection device, the puff detectiondevice senses the puff and activates the internal heater 105. Otherwise,the internal heater 105 may be activated manually. The electric powersupply in the aerosol generating device supplies electrical energy tothe internal heater 105 to heat the liquid in the porous tube 107adjacent the internal heater 105. The liquid in the porous tube 107 isvaporized by the internal heater 105 to create a supersaturated vapourin the internal passageway 103. At the same time, the liquid beingvaporized is replaced by further liquid moving through the porous tube107 from the reservoir. The supersaturated vapour created is mixed withand carried in the air flow from the air inlet through the internalpassageway 103. The vapour condenses to form an inhalable aerosol, whichis carried towards the air outlet and into the mouth of a user.

FIGS. 1 and 2 show one example of a cartridge for use with an aerosolgenerating device according to the present invention. Other examples arepossible, however. The cartridge simply needs to include or receive aliquid aerosol-forming substrate and comprise a vaporizer located atleast partially in the internal passageway of the container andseparated from the liquid by a porous interface at least partiallylining the internal passageway. For example, the vaporizer may notcomprise a heater, in which case another device may be included tovaporize the liquid aerosol-forming substrate. For example, a puffdetection device need not be provided. Instead, the device could operateby manual activation, for example the user operating a switch when apuff is taken. For example, the overall shape and size of the housingcould be altered.

Preferably, the cartridge is disposable and is arranged to cooperatewith an aerosol generating device which is reusable. The cartridge maybe refilled or replaced when the liquid is used. Thus, when the liquidaerosol-forming substrate in the cartridge has been used up, thecartridge may be disposed of and replaced with a new cartridge, or theempty cartridge may be refilled. However, the aerosol generating devicemay not be designed to operate in conjunction with a separate cartridge.Instead, the aerosol generating device may include or receive a liquidaerosol-forming substrate in a storage portion and comprise a vaporizerlocated at least partially in the internal passageway of the liquidstorage portion and separated from the liquid by a porous interface atleast partially lining the internal passageway. That is to say, theaerosol generating device may comprise all the components described inrelation to the cartridge. Additionally, the aerosol generating devicemay comprise an electric power supply and electric circuitry.Preferably, however, there is provided an aerosol generating devicearranged to operate in conjunction with a cartridge. Preferably, theaerosol generating device is reusable and the cartridge is replaceableor refillable. Thus, when the liquid aerosol-forming substrate in thecartridge has been used up, the cartridge may be disposed of andreplaced with a new cartridge, or the empty cartridge may be refilled.

The cartridge shown in FIGS. 1 and 2 has a relatively straightforwardconstruction, which simplifies manufacture. The internal heater 105 isprotected from damage by the container 101 and, because the internalheater 105 is contained within the internal passageway 103 of thecontainer 101 (rather than downstream of the container as in prior artarrangements), the overall length of the cartridge, and hence theaerosol generating device, can be reduced. Moreover, the container 101acts as an insulator thereby preventing the outside of the cartridge,and aerosol generating device, from overheating. Gravity may assist inconveying the liquid in the top part of the container 101 through theporous interface, and the chance of the porous interface drying out isreduced. As the supersatured vapour condenses in the internal passageway103 to form the aerosol, any aerosol droplets which accumulate in theinternal passageway, may be absorbed by the porous interface. Thisenables the accumulating droplets to be reused, which reduced wastage.

The porous tube 107 can be made from a variety of porous materials andpreferably has a known, pre-defined porosity. Examples include a spongeor foam material, ceramic- or graphite-based materials in the form offibres or sintered powders, foamed metal or plastics material, a fibrousmaterial, for example made of spun or extruded fibres, such as celluloseacetate, polyester, or bonded polyolefin, polyethylene, terylene orpolypropylene fibres, nylon fibres or ceramic. Porous tubes of differentporosities can be used to accommodate different liquid suitable physicalproperties such as density, viscosity, surface tension and vapourpressure. The porous tube must be suitable so that the required amountof liquid can be delivered to the heater. In the embodiment shown inFIGS. 1 and 2, the porous tube extends along the length of the internalpassageway. However, this need not be the case and the porous tube mayextend only along part of the internal passageway. The dimensions of theporous tube can be chosen according to the desired operatingcharacteristics of the aerosol generating device, for example, theamount of liquid aerosol-forming substrate desired to be vaporized.

FIG. 3 is a perspective view of a first embodiment of an internal heater105 for use with a cartridge like that shown in FIGS. 1 and 2. Internalheater 105 comprises a first electrical connection portion 301 at afirst end of the internal heater and a second electrical connectionportion 305 at a second end of the internal heater. There is provided afirst electrical connection blade 303 for electrically connecting thefirst electrical connection portion 301 to an electrical power supplyand a second electrical connection blade 307 for electrically connectingthe second electrical connection portion 305 to an electrical powersupply. A heating filament in the form of heating coil 309 extendsbetween the first electrical connection portion 301 and the secondelectrical connection portion 305.

In the embodiment of FIG. 3, the first 301 and second 305 electricalconnection portions and the heating coil 309 are manufactured separatelyand are subsequently joined together, for example by welding. The firstand second electrical connection portions are in the form of hollowtubes of electrically conducting material, although alternative shapesare possible. The heating coil 309 is in the form of a spiral ofelectrically resistive material, although alternative shapes arepossible.

The cylindrical shape of the first 301 and second 305 electricalconnection portions and the heating coil 309 define a cylindrical bore.When the heater is assembled, together with the porous tube, in theinternal passageway of the container, an air flow route is definedthrough the cylindrical bore defined by the internal heater. Therigidity of the first 301 and second 305 electrical connection portions,in particular, assist in maintaining the shape of the internalpassageway 103 and hence the air flow route through the aerosolgenerating device.

Preferably, the internal heater forms a snug fit inside the internalpassageway 103 and porous tube 107. This prevents the internal heaterand porous tube from falling out of the internal passageway, forexample, when the aerosol generating device is shaken or inverted. Inaddition, preferably, the heating coil 309 is in contact with the poroustube when the heater and porous tube are assembled in the internalpassageway of the container. This ensures a good transfer of heat to theliquid aerosol-forming substrate, which allows consistent formation ofthe aerosol. The length of the heating coil 309, and other dimensions ofthe internal heater 105, can be chosen as desired according to therequired amount of heating.

FIG. 4 is a perspective view of a second embodiment of an internalheater 105′ for use with a cartridge like that shown in FIGS. 1 and 2.Internal heater 105′ comprises a first electrical connection portion401, a second electrical connection portion 405 and an electricaljoining portion 409. The electrical joining portion 409 is at a firstend of the internal heater and the first electrical connection portion401 is at a second end of the internal heater. The first electricalconnection portion 401 is joined to the electrical joining portion 409via an elongate portion 411. The second electrical connection portion405 is at the second end of the internal heater adjacent the firstelectrical connection portion 401 and is connected to the electricaljoining portion 409 via a heating filament 413. Heating filament 413extends between the electrical joining portion 409 and the secondelectrical connection portion 405. There is also provided a firstelectrical connection blade 403 for electrically connecting the firstelectrical connection portion 401 to an electrical power supply and asecond electrical connection blade 407 for electrically connecting thesecond electrical connection portion 405 to an electrical power supply.

In the embodiment of FIG. 4, the first 401 and second 405 electricalconnection portions, the electrical joining portion 409 and the heatingfilament 413 are manufactured together from a single sheet ofelectrically resistive material. The sheet of electrically resistivematerial may have any suitable shape. The first 401 and second 405electrical connection portions, the electrical joining portion 409 andthe heating filament 413 may be cut from the sheet of electricallyresistive material, for example, by a laser or by a chemical orelectrical processor by high pressure water jet. Alternatively, thesheet of electrically resistive material may be pre-formed in thedesired shape. Once the sheet has the appropriate shape, the sheet maybe folded, rolled, curved or bent so as to form a cylindrical tube, asshown in FIG. 4.

When the cut sheet of electrically resistive material is rolled to formthe heater, the cylindrical shape of the first 401 and second 405electrical connection portions, the electrical joining portion 409 andthe heating filament 413 define a cylindrical bore. When the heater isassembled, together with the porous tube, in the internal passageway ofthe container, an air flow route is defined through the cylindrical boredefined by the internal heater. The shape of the internal heater assistsin maintaining the shape of the internal passageway 103 and hence theair flow route through the aerosol generating device.

Preferably, the internal heater forms a snug fit inside the internalpassageway 103 and porous tube 107. This prevents the internal heaterand porous tube from falling out of the internal passageway, forexample, when the aerosol generating device is shaken or inverted. Inaddition, preferably, the heating filament 413 is in contact with theporous tube when the heater and porous tube are assembled in theinternal passageway of the container. This ensures a good transfer ofheat to the liquid aerosol-forming substrate, which allows consistentformation of the aerosol. In particular, the construction by rolling ofthe internal heater 105′ may provide a spring or elastic effect,ensuring good contact between the heating filament 413 and the poroustube, when the heater and porous tube are assembled in the internalpassageway. The length of the heating filament 413, and other dimensionsof the internal heater 105, can be chosen as desired according to therequired amount of heating.

In the embodiments of FIGS. 3 and 4, the air flow route is through thecylindrical bore defined by the internal heater. The air flows throughthe centre of the internal heater. That is to say, the size of theinternal passageway and the internal heater defines the size of the airflow route. Thus, the internal passageway and cylindrical bore formed bythe internal heater may act as an aerosol-forming chamber for assistingor facilitating generation of the aerosol. In addition, the size of theinternal passageway and the internal heater may be used to assist withcontrol of the aerosol. A small internal passageway and internal heaterdiameter may result in a high air flow rate through the aerosolgenerating device which may result in smaller droplets in the aerosol. Alarge internal passageway and internal heater diameter, on the otherhand, may result in a low air flow rate through the aerosol generatingdevice which may result in larger droplets. The droplet size in theaerosol may affect the user experience. The size of the internalpassageway and internal heater is preferably pre-set according to theaerosol-forming substrate and the desired aerosol properties.Alternatively, however, the size of the internal passageway and internalheater may be variable by a user.

In one embodiment (not shown), there is provided a nozzle arranged toextend into the internal passageway of the container 101 when thecartridge is received in the aerosol generating device. The nozzle mayform part of the aerosol generating device or part of the cartridge. Thenozzle provides an air inlet into the internal passageway. If theinternal heater defines a cylindrical bore which surrounds the air flowroute, the nozzle may be arranged to extend into the cylindrical boredefined by the internal heater. The nozzle may allow the incoming airflow to be directed. For example, the nozzle may allow the incoming airflow to be directed directly onto the internal heater, directly onto theporous interface, across the surface of the internal heater, across thesurface of the porous interface, or in any other desired direction. Thismay affect the aerosol formation which may, in turn affect the userexperience. In addition, the nozzle may provide an air inlet or inletshaving a small cross section, which will increase the air flow speed.This may also affect the aerosol formation by reducing the droplet sizein the aerosol.

Thus, according to the invention, the aerosol generating device includesa storage portion having an internal passageway, a vaporizer at leastpartially contained in the internal passageway and a porous interface atleast partially lining the internal passageway. This provides a numberof advantages. Embodiments of the aerosol generating device have beendescribed with reference to FIGS. 1 and 2, and embodiments of thevaporizer have been described with reference to FIGS. 3 and 4. Featuresdescribed in relation to one embodiment may also be applicable toanother embodiment.

1. An aerosol generating device, comprising: a storage portionconfigured to store an aerosol-forming substrate, the storage portionhaving an outer housing and an internal passageway, the storage portionforming a reservoir for the aerosol-forming substrate between the outerhousing and the internal passageway; a vaporizer configured to heat theaerosol-forming substrate to form an aerosol, the vaporizer at leastpartially inside the internal passageway in the storage portion; and aporous interface at least partially lining the internal passagewayconfigured to convey the aerosol-forming substrate from the storageportion towards the vaporizer, wherein the aerosol generating device iselectrically operated and the vaporizer comprises an electric heaterconfigured to heat the aerosol-forming substrate, wherein the electricheater comprises: a first electrical connection portion, a secondelectrical connection portion, and a heating filament between the firstand the second electrical connection portions, wherein a cylindricalshape of the first and the second electrical connection portions and theheating filament define a cylindrical bore, and wherein an air flowroute is defined through the cylindrical bore, and wherein the firstelectrical connection portion is a first cylindrical electricalconnection portion, wherein the second electrical connection portion isa second cylindrical electrical connection portion, and wherein theheating filament is a cylindrical heating element.
 2. The aerosolgenerating device according to claim 1, wherein the first and the secondelectrical connection portions are in a form of hollow tubes.
 3. Theaerosol generating device according to claim 2, wherein the firstelectrical connection portion is located at a first end of the internalpassageway, the second electrical connection portion is located at asecond end of the internal passageway, and the heating filament has afirst end joined to the first electrical connection portion and a secondend joined to the second electrical connection portion.
 4. The aerosolgenerating device according to claim 2, wherein the hollow tubes arehollow tubes of electrically conducting material.
 5. The aerosolgenerating device according to claim 1, wherein the heating filament isin contact with the porous interface.
 6. The aerosol generating deviceaccording to claim 1, wherein the electric heater further comprises asheet of electrically resistive material shaped to form the firstelectrical connection portion, the second electrical connection portion,and the heating filament.
 7. The aerosol generating device according toclaim 6, wherein the electric heater further comprises a cylindricalelectrical joining portion, and wherein the cylindrical shape of thefirst and the second electrical connection portions, the cylindricalelectrical joining portion, and the heating filament define thecylindrical bore.
 8. The aerosol generating device according to claim 1,wherein the porous interface comprises a hollow tube of porous material,an outer dimension of the hollow tube being substantially equal to adiameter of the internal passageway of the storage portion.
 9. Theaerosol generating device according to claim 1, further comprising atleast one air inlet and at least one air outlet, the at least one airinlet and the at least one air outlet being arranged so as to define anair flow route from the at least one air inlet to the at least one airoutlet via the internal passageway of the storage portion.
 10. Acartridge, comprising: a storage portion configured to store anaerosol-forming substrate, the storage portion having an outer housingand an internal passageway, the storage portion forming a reservoir forthe aerosol-forming substrate between the outer housing and the internalpassageway; a vaporizer configured to heat the aerosol-forming substrateto form an aerosol, the vaporizer at least partially inside the internalpassageway in the storage portion; and a porous interface at leastpartially lining the internal passageway configured to convey theaerosol-forming substrate from the storage portion towards thevaporizer, wherein the vaporizer comprises an electric heater configuredto heat the aerosol-forming substrate, wherein the electric heatercomprises: a first electrical connection portion, a second electricalconnection portion, and a heating filament between the first and thesecond electrical connection portions, wherein a cylindrical shape ofthe first and the second electrical connection portions and the heatingfilament define a cylindrical bore, and wherein an air flow route isdefined through the cylindrical bore, and wherein the first electricalconnection portion is a first cylindrical electrical connection portion,wherein the second electrical connection portion is a second cylindricalelectrical connection portion, and wherein the heating filament is acylindrical heating element.
 11. The cartridge according to claim 10,wherein the first and the second electrical connection portions are inthe form of hollow tubes.
 12. The cartridge according to claim 11,wherein the first electrical connection portion is located at a firstend of the internal passageway, the second electrical connection portionis located at a second end of the internal passageway, and the heatingfilament has a first end joined to the first electrical connectionportion and a second end joined to the second electrical connectionportion.
 13. The cartridge according to claim 11, wherein the hollowtubes are hollow tubes of electrically conducting material.
 14. Thecartridge according to claim 10, wherein the heating filament is incontact with the porous interface.
 15. The cartridge according to claim10, wherein the electric heater further comprises a sheet ofelectrically resistive material shaped to form the first electricalconnection portion, the second electrical connection portion, and theheating filament.
 16. The cartridge according to claim 15, wherein theelectric heater further comprises a cylindrical electrical joiningportion, and wherein the cylindrical shape of the first and the secondelectrical connection portions, the cylindrical electrical joiningportion, and the heating filament define the cylindrical bore.
 17. Thecartridge according to claim 10, wherein the porous interface comprisesa hollow tube of porous material, an outer dimension of the hollow tubebeing substantially equal to a diameter of the internal passageway ofthe storage portion.
 18. The cartridge according to claim 10, furthercomprising at least one air inlet and at least one air outlet, the atleast one air inlet and the at least one air outlet being arranged so asto define an air flow route from the at least one air inlet to the atleast one air outlet via the internal passageway of the storage portion.19. An aerosol generating system, comprising: a cartridge and an aerosolgenerating device, the cartridge or the aerosol generating devicecomprising a storage portion configured to store an aerosol-formingsubstrate, the storage portion having an outer housing and an internalpassageway, the storage portion forming a reservoir for theaerosol-forming substrate between the outer housing and the internalpassageway; a vaporizer configured to heat the aerosol-forming substrateto form an aerosol, the vaporizer at least partially inside the internalpassageway in the storage portion; and a porous interface at leastpartially lining the internal passageway configured to convey theaerosol-forming substrate from the storage portion towards thevaporizer, wherein the aerosol generating device is electricallyoperated and the vaporizer comprises an electric heater configured toheat the aerosol-forming substrate, wherein the electric heatercomprises: a first electrical connection portion, a second electricalconnection portion, and a heating filament between the first and thesecond electrical connection portions, wherein a cylindrical shape ofthe first and the second electrical connection portions and the heatingfilament define a cylindrical bore, and wherein an air flow route isdefined through the cylindrical bore, and wherein the first electricalconnection portion is a first cylindrical electrical connection portion,wherein the second electrical connection portion is a second cylindricalelectrical connection portion, and wherein the heating filament is acylindrical heating element.